Comparison of in Vitro Release Rates of Nitroglycerin by Diffusion Through a Teflon Membrane to the USP Method

Abstract

The in vitro release profile of nitroglycerin (GTN) from different transdermal patches through synthetic membranes has been determined and compared to the USP adapted release rate method. Five different nitroglycerin transdermal test formulations were compared to commercially available Nitro-Dur®. All formulations display similar release rate profiles when tested by the USP adapted release rate method. In contrast, significant differences among the tested formulations were observed by using a synthetic Teflon membrane. In these studied an attempt was made to develop a simple, reliable, and reproducible method for testing the release of GTN from different transdermal patches in vitro.